Atractylodes macrocephala Koidz is a traditional medicinal plant,which shows antitumor,anti-inflammatory and antioxidant activities. Volatile oils isolated by steam distillation from A. macrocephala Koidz collected from three diverse localities( Zhejiang,Anhui and Gansu Provinces) were studied by gas chromatography-mass spectrometry( GC-MS). A total of 24 volatile constituents were identified. There were 21 common volatile constituents in three samples. The dominant compound in three samples was atractylone...